partedとgdiskを使う

partedによる使用可能セクターの変更

[root]#parted /dev/vdb
GNU Parted 3.1
Using /dev/vdb
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) print
Error: The backup GPT table is not at the end of the disk, as it should be. This might mean that another operating system believes the disk is smaller. Fix, by moving the backup to the end (and
removing the old backup)?
Fix/Ignore/Cancel?
Fix/Ignore/Cancel? Fix
Warning: Not all of the space available to /dev/vdb appears to be used, you can fix the GPT to use all of the space (an extra 83886080 blocks) or continue with the current setting?
Fix/Ignore? Fix
Model: Virtio Block Device (virtblk)
Disk /dev/vdb: 64.4GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags: pmbr_boot
Number Start End Size File system Name Flags
1 1049kB 2097kB 1049kB Linux filesystem bios_grub
2 2097kB 4301MB 4299MB linux-swap(v1) Linux swap
3 4301MB 21.5GB 17.2GB ext4 Linux filesystem
(parted) q